The Sony BRAVIA KDL-46XBR9 is a 46-inch LCD HDTV that was released in 2009 by Sony. Although it is generally considered to be a reliable HDTV, you may find that your Sony BRAVIA KDL-46XBR9 reboots seemingly at random. There are five common causes for KDL-46XBR9 rebooting problems, ranging from issues with the firmware to overheating. By troubleshooting through each potential cause for your BRAVIA's rebooting problem, you can usually get your BRAVIA to function correctly again.
The firmware on the Sony BRAVIA KDL-46XBR9 is the software that powers the TV. The way the TV's menus look and how the TV functions are dictated by the firmware on the BRAVIA. If the firmware on your KDL-46XBR9 is not functioning correctly, this can cause the BRAVIA to reboot for no reason at all. You can generally resolve rebooting caused by firmware problems by following the instructions in the BRAVIA KDL-46XBR9 for updating the firmware on the TV.
Your BRAVIA KDL-46XBR9 comes with a presence sensor, which is responsible for conserving energy by turning off or rebooting the TV automatically. This generally occurs when no motion is detected in front of the TV. If you notice that the rebooting issue is occurring when you are not in the room, it's likely that your presence sensor is functioning correctly. In this case you can either leave the presence sensor on and learn to live with occasional reboots or turn the presence sensor off first by pressing the "Menu" button on your remote and then clicking the "Off" button next to "Presence Sensor."
Although more commonly seen in computers and other similar devices, overheating can also be a problem for some Sony KDL-46XBR9 TVs. When the KDL-46XBR9 overheats, the TV will typically turn itself off in order to avoid further heat damage to the TV's hardware components. If you notice that your KDL-46XBR9 is very hot when the TV reboots, it's likely that your rebooting problem is caused by overheating. You may be able to resolve your overheating problem by putting your TV in a well-ventilated area or by removing dust and other dirt from the back of the TV. If the problem persists, you may need to contact Sony for repair.
Your Sony BRAVIA KDL-46XBR9 TV may reboot due to a damaged AC power cord. In this case you can usually resolve the rebooting problem by replacing the power cord. Your Sony BRAVIA TV may also reboot because of a bad power supply in the TV. This typically happens when the TV has been used a lot for a long time, though it sometimes happens with a brand-new TV as well. You can contact Sony for repair. The BRAVIA KDL-46XBR9 may also reboot because of incorrect settings on the TV. You may be able to fix the settings by opting to "Restore the TV to factory settings" on your TV's Menu Options screen.